1942. The Soviet intelligence officer, senior lieutenant of state security Sergey Skorin, after a four-year stay in Germany, returns to his homeland, however, he is seriously injured during the transition and is forced to spend several months in the hospital. Meanwhile, the German baron, intelligence major Georg von Schlosser, who was not allowed to serve for two years, is finally summoned by the head of the military intelligence service, Admiral Canaris, and entrusted with a secret mission of particular importance. Schlosser goes to Tallinn.

Skorin arrives in Tallinn. According to legend, he is a German officer, Captain Paul Krieger, who arrived on vacation after being wounded and is looking for his lost bride. He quickly realizes that one of his colleagues, radio operator Evelina, posing as a flower seller, is already under surveillance by the Germans. The girl manages to warn in time and she hides. In turn, the Germans manage to intercept the radio signal sent by Skorin to Moscow. Taking into account these circumstances that happened on the same day, Schlosser guesses that his plan is starting to work, the Soviet intelligence agent has arrived and it will not be difficult to figure out his identity.

Simakov informs the Commissar of State Security that Skorin was forced to cut off contact with the underground due to surveillance of the flower girl. To provide him with support, it is proposed to send a former state security officer Konstantin Petrukhin, a close friend of Skorin, to Tallinn. But the commissioner rejects Petrukhin's candidacy, considering him undisciplined. Schlosser is completely convinced of Skorin's personality and begins his game with him. He manages to find the intelligence officer's safe house. The Baron hands Skorin over to the head of the Tallinn Gestapo, Sturmbannfuehrer Franz Maggil.

Skorin continues to send encrypted messages to Moscow. On the recommendation of the baron, he reports that he managed to recruit a cadet of the intelligence school Larin, and also that Schlosser knows that he is a Soviet intelligence officer, but does not take any measures to prevent his activities. Petrukhin arrives in Tallinn and establishes contact with the underground. He asks Uncle Pyotr to find a reliable person who works in a photo studio. Schlosser introduces Skorin to General Staff Colonel Reidlich, a specialist of the East.

State security officers do not know how to regard the information received from Skorin. They believe that it needs to be rechecked and hope that Petrukhin will be able to provide them with additional information. Skorin imitates a binge in front of Schlosser because of his failure. The Baron continues to send ciphers on his behalf. Wanting to convince of the veracity of the information supplied, he reports to Moscow the name of the resident working for the Abwehr.